Administration set detection and authentication using CAM profiles

Abstract

An administration set for an infusion pump includes a free-flow prevention device having a movable plunger that includes a cam surface defining an uneven profile along a direction of movement of the plunger, wherein the shape of the cam surface profile indicates the administration set is authorized for use with the infusion pump and may further indicate the specific type of administration set. A sensor in the infusion pump senses movement of the plunger as a platen of the infusion pump is latched and generates a profile signal in the time domain representative of the cam surface profile. A processor evaluates the profile signal and controls operation of the pump to protect a patient from improper loading of an administration set, use of an unauthorized administration set, and/or use of an invalid type of administration set for a chosen infusion protocol.

What is claimed is: 
     
       1. An apparatus comprising:
 an infusion pump including a pumping mechanism, an actuating member, and a sensor; and 
 an administration set including tubing for conveying an infusion liquid and a free-flow prevention device operable to selectively stop and permit flow of the infusion liquid through the tubing; 
 wherein the free-flow prevention device includes a carrier and a plunger movable relative to the carrier between an open position permitting flow of the infusion liquid through the tubing and a closed position stopping flow of the infusion liquid through the tubing, the plunger being biased toward the closed position and having a cam surface defining a profile along a direction of movement of the plunger; 
 wherein a segment of the tubing is loadable into the infusion pump for engagement by the pumping mechanism; 
 wherein the free-flow prevention device is loadable into the infusion pump and is operated by the actuating member, the actuating member being movable from a non-pumping position to a pumping position thereby moving the plunger from the closed position to the open position; 
 wherein the sensor is arranged to sense movement of the plunger, and the sensor generates a profile signal in the time domain representative of the cam surface profile. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the cam surface profile includes a first plateau and a second plateau having different respective elevations. 
     
     
       3. The apparatus according to  claim 2 , wherein the first plateau and the second plateau have different respective lengths in the direction of movement. 
     
     
       4. The apparatus according to  claim 2 , wherein the cam surface profile further includes a topographical feature between the first plateau and the second plateau. 
     
     
       5. An apparatus comprising:
 an infusion pump including a pumping mechanism, an actuating member, and a sensor; and 
 an administration set including tubing for conveying an infusion liquid and a free-flow prevention device operable to selectively stop and permit flow of the infusion liquid through the tubing; 
 wherein the free-flow prevention device includes a carrier and a plunger movable relative to the carrier between an open position permitting flow of the infusion liquid through the tubing and a closed position stopping flow of the infusion liquid through the tubing, the plunger being biased toward the closed position and having a cam surface defining a profile along a direction of movement of the plunger; 
 wherein a segment of the tubing is loadable into the infusion pump for engagement by the pumping mechanism; 
 wherein the free-flow prevention device is loadable into the infusion pump and is operated by the actuating member, the actuating member being movable from a non-pumping position to a pumping position thereby moving the plunger from the closed position to the open position; 
 wherein the sensor is arranged to sense movement of the plunger, and the sensor generates a profile signal in the time domain representative of the cam surface profile, 
 wherein the infusion pump further comprises: 
 a memory storing predetermined reference values; and 
 a processor arranged to receive the profile signal, wherein the processor is programmed to compare the profile signal to the stored reference values and determine whether or not the administration set is loaded in the infusion pump and whether or not the administration set is authorized for use with the infusion pump, based on the comparison. 
 
     
     
       6. The apparatus of  claim 5 , wherein the processor is programmed such that the processor sends a command disabling operation of the infusion pump if the administration set is not loaded in the infusion pump or the administration set is not authorized for use with the infusion pump. 
     
     
       7. The apparatus to  claim 5 , wherein the processor is further programmed to determine a type of the administration set from among a plurality of administration set types based on the comparison. 
     
     
       8. The apparatus of  claim 7 , wherein the processor is programmed such that the processor sends a command disabling operation of the infusion pump if the determined type of administration set is incompatible with a desired infusion protocol entered into the infusion pump by a user. 
     
     
       9. The apparatus according to  claim 7 , wherein a first time interval of the profile signal is evaluated to determine whether or not the administration set is loaded and is authorized, and a second time interval of the profile signal different from the first time interval is evaluated to determine the type of the administration set. 
     
     
       10. The apparatus according to  claim 9 , wherein the first time interval and the second time interval overlap one another. 
     
     
       11. An apparatus comprising:
 an infusion pump including a pumping mechanism, an actuating member, and a sensor; and 
 an administration set including tubing for conveying an infusion liquid and a free-flow prevention device operable to selectively stop and permit flow of the infusion liquid through the tubing; 
 wherein the free-flow prevention device includes a carrier and a plunger movable relative to the carrier between an open position permitting flow of the infusion liquid through the tubing and a closed position stopping flow of the infusion liquid through the tubing, the plunger being biased toward the closed position and having a cam surface defining a profile along a direction of movement of the plunger; 
 wherein a segment of the tubing is loadable into the infusion pump for engagement by the pumping mechanism; 
 wherein the free-flow prevention device is loadable into the infusion pump and is operated by the actuating member, the actuating member being movable from a non-pumping position to a pumping position thereby moving the plunger from the closed position to the open position; 
 wherein the sensor is arranged to sense movement of the plunger, and the sensor generates a profile signal in the time domain representative of the cam surface profile, 
 the apparatus further comprising a follower in continuous engagement with the cam surface of the plunger while the free-flow prevention device is loaded in the infusion pump, wherein the cam surface of the plunger slidably engages the follower to displace the follower as the plunger is moved from the closed position to the open position, and the sensor is responsive to the displacement of the follower.